Certainly, it's good for spiders to hit
'Recent Changes', and often.
Why? The spider doesn't know that the pages on RecentChanges have had
recent changes. It's just a list of links, like special:allpages or
special:ShortPages.
Maybe one could add
/wiki/special:RecentChanges&
to the robots.txt file; that way, the spider would fetch only one copy
of RecentChanges, not 14.
Axel